import cv2
import numpy as np
img = cv2.imread("images/008.jpg", cv2.IMREAD_GRAYSCALE)
# cv2.imwrite("images/gray_008.jpg", img)
cv2.imshow("test", img)
key = 0
# 27：ESC
while key != 27:
    key = cv2.waitKey()
cv2.destroyWindow("test")

# cv2.waitKey()



